Within hard disk drives (HDDs), a preamplifier or preamp is generally used to perform read and write operations with a magnetic head. Typically, for write operations, the preamplifier generates a current waveform that uses a DC current to polarize magnetic elements within the disk and overshoot components to compensate for losses within the head. Turning to FIG. 1, an example of a conventional preamplifier or preamp 100 can be seen. Preamp 100 is commonly employed in hard disc drive (HDD) applications for providing write signals to a magnetic head (which is typically an inductive load). This preamp 100 is generally comprised of input buffers 102-1 and 102-2 and digital logic 104 (which includes duration generators 106-1 and 106-2, logic circuits 108-1 and 108-2, and an H-bridge). While this preamp 100 effectively drives the magnetic head, there are some issues. Namely, this type of preamp 100 can be costly because it is usually produced in a silicon-germanium (SiGe) process. This preamp 100 can consume a large amount of power and can require large supply voltages (i.e., 8V or 10V). Therefore, there is a need for an improved preamplifier.
Some other examples of conventional systems are: U.S. Pat. No. 6,285,221; U.S. Pat. No. 7,408,313; U.S. Pat. No. 7,656,111; U.S. Pat. No. 7,880,989.